1. Field of the Invention
The present invention relates to a coating layer structure for heat-cookers, and more particularly, to a coating layer structure for heat-cookers wherein said structure has been produced by forming an aluminum oxide (Al2O3) layer on the surface of an aluminum heat-cooker by anodic oxidation and then applying thereon either an anion- and far infrared ray-emitting, inorganic ceramic coating agent or a non-stick, inorganic ceramic coating agent, said both coating agents being non-toxic to human body, and whereby said structure, on heating, does not release any carcinogens and increases heat conductivity at the same time, and said structure also has excellent anti-corrosive and anti-abrasive properties.
2. Description of the Related Art
Generally, an aluminum heat-cooker may take a variety of forms, although for its washability and for preventing food from adhering thereto during cooking, it is used in such a form that the surface to be coated is endowed with roughness by sandblastering to increase the surface area and then is painted with Teflon and the like. However, the production of fine pin holes is inevitable during the Teflon painting, which leads to a problem that aluminum erodes through pin holes, and the like when cooking or maintaining salt-containing, acidic or alkaline food.
Also, in order to resolve the above problem, Korean Registered Utility Model No. 206737 (registration date: May 24, 2000) provides an aluminum cooker, on the surface of which aluminum oxide film layer and Teflon coating layer are formed sequentially wherein the former is formed by anodic oxidation (anodizing), thereby providing such advantages as enhanced adhesive strength between the surface of the cooker and the Teflon coating layer and prevention of food from adhering to the surface. However, in terms of the weakness of the surface strength of said Teflon itself, such cooker loses its original function at an earlier stage because of surface abrasions and scratches, and the like due to the frequent use of a spoon or a metallic spatula, and the like by the nature of a heat-cooker. Also, as it has recently been known that carcinogens are released from Teflon, the use of cookers coated with Teflon is being avoided.
Especially, the U.S. Environmental Protection Agency (EPA) has requested manufacturers to stop producing perfluorooctanoic acid (PFOA), a material used to make Teflon which is used as a coating agent for a frying pan, and the like. Along with such request to stop producing PFOA by 2015, the EPA has first requested eight general chemical companies including Dupont and 3M to reduce the use of said material by 95% by 2010. Dupont has already announced that they would accept this request. Accordingly, there is an enormous need for aluminum heat-cookers, on the surface of which an alternative coating layer is formed, wherein said coating layer is non-toxic to human body, prevents food from adhering thereto and shows a good heat conductivity.